Resource assignment and packet collision avoidance in sidelink communications

Abstract

Certain aspects of the present disclosure provide techniques for resource block assignment and packet collision avoidance in sidelink communications. A method that may be performed by a first user equipment (UE) generally includes determining at least a first set of resources for a second UE overlaps at least a second set of resources for a third UE. The method generally includes broadcasting an indication of overlapping resources to at least the second UE and the third UE.

1 . A method for wireless communication by a first user equipment (UE), comprising:
 determining at least a first set of resources for a second UE overlaps at least a second set of resources for a third UE; and   broadcasting an indication of the overlapping resources to at least the second UE and the third UE.   
     
     
         2 . The method of  claim 1 , wherein:
 determining the at least a first set of resources for the second UE overlaps the at least a second set of resources for the third UE comprises determining overlap for a plurality of sets of resources for a plurality of UEs; and   broadcasting an indication of the overlapping resources to at least the second UE and the third UE comprises broadcasting the indication of the overlapping resources to the plurality of UEs.   
     
     
         3 . The method of  claim 1 , wherein determining the first set of resources for the second UE overlaps the second set of resources for the third UE comprises:
 receiving a first resource allocation information from the second UE indicating the first set of resources;   receiving a second resource allocation information from the third UE indicating the second set of resources; and   determining the overlap based on the first and second resource allocation information.   
     
     
         4 . The method of  claim 3 , wherein receiving the first and second resource allocation information comprising receiving the first and second resource allocation information via one of one or more physical sidelink control channel (PSCCH) transmissions and one or more physical sidelink shared channel (PSSCH) transmissions. 
     
     
         5 . The method of  claim 3 , wherein determining the first set of resources for the second UE overlaps the third set of resources for the third UE comprises:
 monitoring transmission from the second UE using the first set of resources;   monitoring transmission from the third UE using the second set of resources; and   determining the overlap based on the monitoring.   
     
     
         6 . The method of  claim 5 , further comprising:
 unsuccessfully decoding the transmission from the second UE, the third UE, or both.   
     
     
         7 . The method of  claim 1 , wherein the first and second sets of resources comprise semi-persistently scheduled (SPS) resource blocks (RBs). 
     
     
         8 . The method of  claim 1 , wherein broadcasting the indication comprises broadcasting the indication via one of a physical sidelink control channel (PSCCH) transmissions and a physical sidelink shared channel (PSSCH). 
     
     
         9 . The method of  claim 1 , further comprising:
 in response to broadcasting the indication of the overlapping resources, receiving updated resource allocation information from each of the second UE and the third UE.   
     
     
         10 . The method of  claim 1 , wherein the first UE, the second UE, and the third UE comprise vehicle-to-anything (V 2 X) capable UEs. 
     
     
         11 . The method of  claim 1 , wherein the first UE, the second UE, and the third UE are configured for sidelink transmission mode 4 vehicle-to-anything (V 2 X) communications via a sidelink channel, and wherein the first UE, the second UE, and the third UE autonomously allocate resources for transmission. 
     
     
         12 . A method for wireless communication by a first user equipment (UE), comprising:
 determining a first set of resources allocated for transmission by the first UE;   receiving a broadcast from a second UE of an indication of one or more resources of the first set of resources overlapping one or more resources of a second set of resources allocated for transmission by a third UE; and   in response to the indication:
 stopping transmission on at least the one or more overlapping resources; and 
 determining a third set of resources allocated for transmission by the first UE, the third set of resources excluding the one or more overlapping resources. 
   
     
     
         13 . The method of  claim 12 , wherein receiving the broadcast from the at least the second UE of the indication comprises:
 receiving broadcast from a plurality of UEs of an indication of one or more resources of the first set of resources overlapping one or more resources of a plurality of sets of resources for the plurality of UEs.   
     
     
         14 . The method of  claim 12 , wherein determining the first set of resources, the second set of resources, or both, comprises:
 determining semi-persistently scheduled (SPS) resource blocks (RBs).   
     
     
         15 . The method of  claim 14 , wherein determining the SPS RBs comprises autonomously selecting the SPS RBs according to a preconfigured SPS algorithm. 
     
     
         16 . The method of  claim 12 , further comprising:
 transmitting resource allocation information to the second UE indicating the first set of resources, wherein the broadcast from the second UE is received in response to the resource allocation information.   
     
     
         17 . The method of  claim 16 , wherein transmitting the resource allocation information comprises transmitting the resource allocation information via one of a physical sidelink control channel (PSCCH) transmission and a physical sidelink shared channel (PSSCH). 
     
     
         18 . The method of  claim 12 , wherein receiving the broadcast of the indication comprises receiving the broadcast of the indication via one of a physical sidelink control channel (PSCCH) transmission and a physical sidelink shared channel (PSSCH). 
     
     
         19 . The method of  claim 12 , wherein determining the first set of resources comprises:
 detecting a set of available resources; and   selecting the one or more resources of the first set of resources from the set of available resources.   
     
     
         20 . The method of  claim 19 , wherein determining the third set of resources comprises:
 updating the set of available resources by removing the one or more overlapping resources from a set of available resources; and   selecting the third set of resources from the updated set of available resources.   
     
     
         21 . The method of  claim 12 , wherein the first UE, the second UE, and the third UE comprise vehicle-to-anything (V 2 X) capable UEs. 
     
     
         22 . The method of  claim 12 , wherein the first UE, the second UE, and the third UE are configured for sidelink transmission mode 4 vehicle-to-anything (V2X) communications via a sidelink channel, and wherein the first UE, the second UE, and the third UE autonomously allocate resources for transmission. 
     
     
         23 . An apparatus for wireless communication, comprising:
 at least one processor configured to:
 determine a first set of resources for a first user equipment (UE) overlaps a second set of resources for a second UE; and 
 broadcast an indication of the overlapping resources to the first UE and the second UE; and 
   a memory coupled with the at least one processor.   
     
     
         24 . The apparatus of  claim 23 , wherein determining the at least a first set of resources for the first UE overlaps the at least a second set of resources for the second UE comprises means for determining overlap for a plurality of sets of resources for a plurality of UEs; and
 broadcasting an indication of the overlapping resources to at least the first UE and the second UE comprises means for broadcasting the indication of the overlapping resources to the plurality of UEs.   
     
     
         25 . The apparatus of  claim 23 , wherein determining the first set of resources for the first UE overlaps the second set of resources for the second UE comprises:
 receiving a first resource allocation information from the first UE indicating the first set of resources;   receiving a second resource allocation information from the second UE indicating the second set of resources; and   determining the overlap based on the first and second resource allocation information.   
     
     
         26 . The apparatus of  claim 25 , wherein determining the first set of resources for the first UE overlaps the second set of resources for the second UE comprises:
 monitoring transmission from the first UE using the first set of resources;   monitoring transmission from the second UE using the second set of resources; and   determining the overlap based on the monitoring.   
     
     
         27 . An apparatus for wireless communication, comprising:
 at least one processor configured to:
 determine a first set of resources allocated for transmission by the apparatus; 
 receive a broadcast from a first user equipment (UE) of an indication of one or more resources of the first set of resources overlapping one or more resources of a second set of resources allocated for transmission by a second UE; and 
 in response to the indication:
 stop transmission on at least the one or more overlapping resources; and 
 determine a third set of resources allocated for transmission by the apparatus, the third set of resources excluding the one or more overlapping resources; and 
 
   a memory coupled with the at least one processor.   
     
     
         28 . The apparatus of  claim 27 , wherein receiving the broadcast from the at least the second UE of the indication comprises:
 receiving broadcast from a plurality of UEs of an indication of one or more resources of the first set of resources overlapping one or more resources of a plurality of sets of resources for the plurality of UEs.   
     
     
         29 . The apparatus of  claim 27 , wherein the at least one processor is further configured to:
 transmit resource allocation information to the second UE indicating the first set of resources, wherein the broadcast from the second UE is received in response to the resource allocation information.   
     
     
         30 . The apparatus of  claim 27 , wherein determining the first set of resources comprises:
 detecting a set of available resources; and   selecting the one or more resources of the first set of resources from the set of available resources.